Switchable Supracolloidal 3D DNA Origami Nanotubes Mediated through Fuel/Antifuel Reactions

3D DNA origami provide access to the de novo design of monodisperse and functional bio(organic) nanoparticles, and complement structural protein engineering and inorganic and organic nanoparticle synthesis approaches for the design of self-assembling colloidal systems. We show small 3D DNA origami nanoparticles, which polymerize and depolymerize reversibly to nanotubes of micrometer lengths by applying fuel/antifuel switches. 3D DNA nanocylinders are engineered as basic building block with different numbers of overhang strands at the open sides to allow for their assembly via fuel strands that bridge both overhangs, resulting in the supracolloidal polymerization. The influence of the multivalent interaction patterns and the length of the bridging fuel strand on efficient polymerization and nanotube length distribution is investigated. The polymerized multivalent nanotubes disassemble through toehold-

mediated rehybridization by adding equimolar amounts of antifuel strands. Finally, Förster Resonance Energy Transfer yields in situ insights into the kinetics and reversibility of the nanotube polymerization and depolymerization.